Hey I have some digital inputs which I wanted to convert it into analog signals and send it to Industrial Valve to control the flow of water but because of not familiar with digital to analog conversion I am finding out the best way which help me to convert my digital input to analog output and send the signals to valve and make it run according to the signals
Your Intel will be very helpful
Hi Edward,
We do use our ARM based IRIS BOX PC industrial computer to control flow using a proportiona valve, but I do not understand the reason to use digital inputs as a set up value.
Usually, the flow real value is input into the controller as an analog input in a 4 to 20 mA range format. This would be the real time value to compare with the set up value input coming from an operator panel if configurable set up is required.
To reduce cost, is possible to control the flow with a couple of impulse outputs as a cheaper option, but the more standard way to do it is the one you mention in your post.
We do manufacture industrial input/output boards to interface between ARM and field actuators/sensors. Please have a look to:
Hope it helps.
Iñaki
The most common way to output "analog" on microcontrollers is through PWM where 100% duty cycle corresponds to VDD and 0% is 0V. You can filter the PWM signal to get analog DC output. Almost all microcontrollers support this.
If your microcontroller has a DAC, you can use it to output pure analog signal. check your microcontrollers hardwaree abstraction libraries for the exact code needed.
You also need to make sure your setup can provide the current the valve draws to work. In the case of PWM, you can use a transistor as a switch so that you draw current from VDD instead of through the microcontroller. If you use DAC, you'll need to use an amplifier circuit.
Hope this helps
-Husam